汉防己甲素联合5-FU聚乳酸微球对兔PVR IL-1β和TNF-α表达的影响

目的:探讨汉防己甲素(tetrandrine,Tet)联合5-FU聚乳酸微球对兔增生性玻璃体视网膜病变(proliferati vevitreoretinopathy,PVR)IL-1β和TNF-α表达的影响。方法:随机分为A,B,C3组,建立兔眼外伤性PVR模型,向玻璃体中后部注入药物,A组注入含有Tet联合5-氟尿嘧啶(5-FU)聚乳酸微球的BSS悬浮液0.2mL,B组注入含有5-FU聚乳酸微球的BSS悬浮液0.2mL,C组注入25mg无药物聚乳酸微球的BSS悬浮液0.2mL,术后每天观察眼底变化,必要时行B超检查直到注药后第28d。分别于术后7,14,28d等3个时间点抽取各术眼玻璃体液0.2mL,酶联免疫吸附法(ELISA)检测玻璃体液中TNF-α,IL-2的含量。结果:Tet联合5-FU聚乳酸微球组与5-FU聚乳酸微球组及空白微球组相比,其玻璃体液中TNF-α,IL-2等炎性因子的含量也显著低于其他两组,方差分析P<0.01,差异有统计学意义。结论:Tet在眼内能够降低炎性因子TNF-α和IL-1β的表达,说明Tet可能通过在PVR炎症期发挥抗炎作用,抑制眼内炎症因子的释放,减弱炎症因子对炎性细胞的激活和趋化,从而起到降低PVR发生率的协同作用。     

Safety and pharmacokinetics of a preservative-free triamcinolone acetonide formulation for intravitreal administration

PURPOSE: The safety and pharmacokinetics of a triamcinolone acetonide (TA) preservative-free (TA-PF) formulation were investigated after intravitreal administration in rabbits. METHODS: A TA-PF formulation was prepared as a sterile 40-mg/mL or 160-mg/mL suspension in single-use vials by adding TA powder to 0.5% hydroxypropyl methylcellulose in normal saline. TA-PF (4-mg and 16-mg doses) and Kenalog (Bristol-Myers-Squibb, Princeton, NJ) (4-mg dose) were injected into the vitreous of separate groups of rabbits, and drug levels were measured in the vitreous over time with HPLC. Ocular toxicology (clinical examination, serial electroretinography, and histopathologic analysis) was evaluated in a separate group of animals after intravitreal TA-PF injection. RESULTS: The half-lives of the injection amount in the vitreous, 4-mg TA-PF, 16-mg TA-PF, and 4-mg Kenalog, were found to be 24 days, 39 days, and 23 days, respectively. There were no signs of toxicities by clinical examination after TA-PF injection. Serial electroretinograms of rabbits receiving either 4-mg or 16-mg intravitreal TA-PF injections remained normal over time. Histopathologic analysis showed normal ocular tissues in animals receiving either 4-mg or 16-mg intravitreal TA-PF injections. CONCLUSION: The half-life of TA in the vitreous after a 4-mg injection of either TA-PF or Kenalog was comparable. A 16-mg dose of TA-PF produced a long vitreous half-life, and this may be of clinical benefit in patients requiring 6 months of drug exposure in the eye for a chronic disease.     

Safety of in vivo pharmacologic vitreolysis with recombinant microplasmin in rabbit eyes

PURPOSE: To investigate the safety of intravitreal microplasmin in rabbits and to confirm previous findings of posterior vitreous detachment (PVD). METHODS: Different doses of microplasmin, from 12.5 microg to 250 microg, in 0.1 mL balanced salt solution (BSS) were injected into the vitreous cavity of rabbit eyes to induce PVD. Fellow eyes were injected with the same volume of BSS. Slit-lamp biomicroscopy, ophthalmoscopic fundus examinations, A- and B-mode ultrasonography, and electroretinography were performed to assess the retina. Electroretinograms (ERGs) were recorded up to 90 days after injection. Morphologic alterations were assessed by light microscopy, scanning electron microscopy (SEM), and transmission (TEM) electron microscopy. RESULTS: A slight aqueous flare and cells were observed in the anterior chamber after microplasmin and BSS injection. A slight inflammatory reaction was also observed transiently in the vitreous cavity. In control eyes, B-mode ultrasonography and SEM examination demonstrated that PVD did not develop after BSS injection. Intravitreal injections of 125 microg or greater of microplasmin induced complete PVD with an internal limiting membrane (ILM) devoid of vitreous collagen fibrils. Eyes injected with 12.5 microg microplasmin had partial PVD, and SEM showed residual fibrils covering the ILM. In all eyes, there was a transient reduction in the a- and b-waves of the ERG on days 2 through 7. The ERGs showed less effect with < 250 microg microplasmin. CONCLUSIONS: Intravitreal injection of recombinant microplasmin in the rabbit induces no ERG or retinal ultrastructural abnormalities. Pharmacologic vitreolysis with this agent may be a useful adjunct to vitreous surgery and could be used to induce PVD without vitreous surgery.     

Pharmacokinetics of intraocular drug delivery by periocular injections using ocular fluorophotometry

PURPOSE: To evaluate the pharmacokinetics of the periocular injections: posterior subtenon (PST), retrobulbar (RB), and subconjunctival (SC) injection. METHODS: Two sodium fluorescein (NaF) concentrations, 2.5 mg in 0.1 mL (NaF1) and 2.5 mg in 0.5 mL (NaF2) were injected into live rabbits by the PST (NaF1 n = 4, NaF2 n = 3), RB (NaF1 n = 10), SC (NaF1 n = 6), and intravenous (IV, NaF1 n = 6) routes and into euthanatized rabbits by the RB (NaF1 n = 8) route. NaF concentrations in the choroid/retina, vitreous, and anterior segment were measured by ocular fluorophotometry. The NaF level in the contralateral choroid/retina was used as a measure of the systemic drug levels. RESULTS: The maximum NaF concentrations (nanograms per milliliter) in the choroid/retina after PST, RB, SC, and IV were 757 +/- 549 at 2 hours, 906 +/- 1014 at 1 hour, 320 +/- 462 at 2 hours, and 865 +/- 363 at 5 to 10 minutes, respectively. The PST had the highest and most prolonged vitreous NaF1 concentration (maximum: 270 +/- 226 ng/mL at 3.5 hours). The contralateral peak choroid/retina NaF levels after the RB, SC, and IV injections were 7, 4, and 21 times greater than after the PST injection. The SC injection had the highest anterior segment NaF concentration (5364 +/- 2840 ng/mL at 2 hours). PST with NaF2 resulted in intraocular NaF levels higher than with NaF1. CONCLUSIONS: NaF reaches the choroid/retina by transscleral diffusion from the periocular depot. The orbital and conjunctival vasculature and lymphatics have a larger role in NaF clearance than does the choroid. NaF diffuses into the vitreous from the choroid and the anterior segment; the periocular depot location determines the predominant diffusion pathway. The duration of high NaF levels in the choroid/retina or the anterior segment determines vitreous NaF levels. PST is the best periocular route for vitreous NaF delivery with minimal systemic levels. Increasing the volume of NaF PST depot enhances transscleral drug delivery.     

Vitreous dynamics: vitreous flow analysis in 20-, 23-, and 25-gauge cutters

PURPOSE: To evaluate porcine vitreous flow and balanced saline solution (BSS) flow rates in different vitrectomy systems. METHODS: Porcine vitreous was obtained within 24 hours of slaughter. A high-speed (2 samples/s) balance, precise to 0.01 g, was used. Variable cut rates and vacuum pressures were analyzed in vitreous and BSS. The vitreous was labeled with glass microspheres and triamcinolone acetonide. A high-speed (400 frames/s) camera was used to record cutting for each condition. RESULTS: For all cutters, there was no vitreous flow at zero cut rates (off). In 25-gauge cutters, at 500 mmHg of vacuum, the electric cutter produced higher average flow rates at high cut rates (600 cpm, 0.004 mL/s, and 1500 cpm, 0.013 mL/s) than pneumatic, which demonstrated a decreased flow at speeds higher than 1000 cpm (1000 cpm, 0.015 mL/s, and 1500 cpm, 0.006 mL/s). The percentage of vitreous flow rate/BSS flow rate in different aspiration and cut rates showed an ascending curve. This demonstrates evidence of flow obstruction in 25- (all cut rates), 23- (all cut rates), and 20-gauge (all cut rates). Flow obstruction and surge movements were seen in the high-speed videos. CONCLUSIONS: The vitrectomy systems each illustrate different performances of vitreous removal. The physical characteristics of vitreous resulted in nonuniform flow in all vitreous cutters.     

透明质酸酶对外伤性玻璃体积血转归的影响

目的探讨透明质酸酶对兔眼外伤性玻璃体积血转归的影响。方法28只新西兰白兔,右眼为外伤性玻璃体积血模型,左眼为空白对照眼。1d后随机分为实验组和阳性对照组,每组14只兔（14只眼）。实验组玻璃体腔注射透明质酸酶0．002umol／（min·L）,阳性对照组玻璃体腔注射0．1mL BSS。分别于给药后1、3、7、14、21、28d测量眼压,行裂隙灯及眼底检查。每组抽取2只实验兔行眼球摘除,抽取玻璃体液测定碱性成纤维细胞生长因子（bFGF）的质量浓度,取眼球壁行组织病理学检查。结果给药14d后,实验组的玻璃体混浊程度明显低于阳性对照组,各组间比较差异有统计学意义（P〈0．05）。给药后1d、3d,实验组眼压和空白对照组眼压比较差异均有统计学意义（P〈0．05）,与阳性对照组比较差异均有统计学意义（P〈0．05）。随着时间推移,玻璃体中bFGF的质量浓度均增高,阳性对照组增高更明显。组织病理学检查见实验组和阳性对照组视网膜均出现了水肿和神经节细胞空泡样变、内界膜增厚等改变,但实验组较阳性对照组形成增生膜少。结论透明质酸酶20IU于兔眼玻璃体腔内注射对视网膜无毒性作用,可加速外伤性玻璃体积血的消散,造成眼压一过性降低。     

Prophylaxis of experimental Pseudomonas aeruginosa endophthalmitis after vitrectomy using ceftazidime in the irrigating solution

Purpose: To test the efficacy of ceftazidime in irrigating solution during vitrectomy to prevent experimental Pseudomonas aeruginosa endophthalmitis. Methods: Thirty-two rabbit eyes were divided into 6 groups. Vitrectomy using one of two different irrigating solutions was followed by intravitreal injection of P. aeruginosa: Group 1, balanced salt solution (BSS) followed by 100 colony-forming units (CFU) P. aeruginosa; Group 2, BSS fortified with ceftazidime 175 μg/mL (CBSS) followed by intravitreal injection of 100 CFU P. aeruginosa; Group 3, BSS followed by 500 CFU P. aeruginosa; Group 4, CBSS followed by 500 CFU P. aeruginosa; Group 5, BSS followed by 5000 CFU P. aeruginosa; and Group 6, CBSS followed by 5000 CFU P. aeruginosa. The eyes were examined clinically. Vitreous samples were cultured and histology was performed. Results: Group 1: Three of 5 eyes showed mild to moderate vitreous opacities. Group 2: No vitreous opacities developed. Group 3: All eyes demonstrated endophthalmitis. Group 4: All 6 eyes had clear vitreous with visible fundus. Group 5: Severe endophthalmitis occurred in all 6 eyes. Group 6: Four eyes had clearly visible fundus, 2 eyes had hazy vitreous with red reflex of the fundus. Bacterial growth in groups 3, 4, 5, and 6 was seen in 4/4, 1/6, 6/6, and 0/6 eyes, respectively. Conclusion: When 100-5000 CFU P. aeruginosa were injected after vitrectomy, ceftazidime in the irrigating solution inhibited the signs of intraocular inflammation, and the rate of positive bacterial culture. This revised version was published online in July 2006 with corrections to the Cover Date.     

An in vitro study of ceftazidime and vancomycin concentrations in various fluid media: implications for use in treating endophthalmitis

PURPOSE: To investigate the precipitation process of a mixture of vancomycin and ceftazidime by equilibrium dialysis and determine its subsequent effect on the level of free antibiotics for treatment of endophthalmitis. METHODS: Concentrations of vancomycin and ceftazidime in an equilibrium dialysis chamber were measured during the equilibrium process by high-performance liquid chromatography. Normal saline (NS), balanced salt solution (BSS), and vitreous were used separately as the medium of dialysis. RESULTS: Precipitation of ceftazidime occurred at 37 degrees C but not at room temperature and did not affect the pH of the medium. It formed precipitate on its own or when mixed with vancomycin in all the three media of NS, BSS, and vitreous. More precipitation was formed if ceftazidime was initially prepared in BSS than in NS. After 168 hours in the dialysis chambers, ceftazidime prepared in NS precipitated to 54% of that in vitreous, compared with 88% if prepared in BSS. At 48 hours, ceftazidime prepared in NS decreased from an initial concentration of 137.5 to 73.4 microg/mL in vitreous medium and to 6.3 microg/mL if prepared in BSS. Precipitation of vancomycin was negligible. CONCLUSIONS: Based on this in vitro investigation, ceftazidime precipitates in vitreous at body temperature, regardless of the presence of vancomycin. NS is preferred to BSS as a preparation medium for antibiotics for intravitreal injection, because the extent of ceftazidime precipitation is less. However, due to precipitation, the concentration of free ceftazidime in vitreous may not be sufficiently high for antibacterial activity against most common organisms.     

蛇毒纤溶酶诱导兔眼玻璃体后脱离的实验研究

目的观察蛇毒纤溶酶是否可以诱导兔眼玻璃体后脱离（PVD）,并评价其对视网膜的毒性作用。方法根据随机数字表法将24只新西兰白兔分为A、B、C、D组,每组6只。左眼玻璃体腔注射0.1mL生理盐水作为对照。右眼玻璃体腔分别注入1000U/mL（商品单位）的蛇毒纤溶酶0.04、0.05、0.08、0.1mL,术后1、3、7d通过裂隙灯、间接检眼镜检查,观察眼前后节的变化。术后7d通过组织病理学检查,观察药物注入后是否诱发PVD,并评价其对视网膜结构的影响。结果术后7d对照眼无PVD形成,光学显微镜下见各实验组均有不同程度的部分性PVD形成。A、B、C组的视网膜结构与对照组比较无明显改变;D组可见局限性视网膜内界膜溶解破坏,局部视网膜隆起变薄及脉络膜下渗出的毒性改变。A组和D组的扫描电镜结果与光学显微镜一致。随着玻璃体腔蛇毒纤溶酶注射剂量的增加,玻璃体液化程度加大,PVD的范围也加大。结论兔眼玻璃体腔注射适当剂量的蛇毒纤溶酶,在术后7d可以诱导部分性PVD的形成,且视网膜形态无明显改变。大剂量应用时可见视网膜结构的毒性改变。     

In vivo and in vitro feasibility studies of intraocular use of seprafilm to close retinal breaks in bovine and rabbit eyes

PURPOSE: Seprafilm, a sodium hyaluronate/carboxymethylcellulose absorbable barrier developed to prevent adhesions after abdominal surgery, adheres well to wet tissue. The authors studied the efficacy of this film for sealing retinal breaks in animals. METHODS: In an in vitro study, a retinal detachment with a hole was created in bovine eyecups after the vitreous gel was removed. Seprafilm was placed over the retinal hole, and the strength of the retinal adhesion was measured by pulling the film. Permeability was tested by applying methylene blue to the film covering the retinal break. Seprafilm also was soaked in balanced salt solution (BSS) incubated at 37 degrees C, and the pH of the BSS containing Seprafilm was measured as it melted. In an in vivo study, Seprafilm was powdered and mixed in BSS solution, and 0.1 mL was injected into the right vitreous cavity in study rabbits. The same amount of BSS was injected into the right vitreous cavity in control rabbits. Ophthalmologic examinations were performed. Bilateral electroretinograms were recorded simultaneously before and 6 weeks after injection. Both eyes were enucleated for histologic evaluation. RESULTS: Seprafilm adhered well to the retina, was impermeable to methylene blue, and remained solid in BSS for 30 days before it dissolved, and its pH ranged from 7.2 to 8.0. No intraocular inflammatory reaction occurred after intravitreous injection of Seprafilm solution. There was no significant difference in amplitudes or implicit times of electroretinogram a-waves, b-waves, and oscillatory potentials before and after injection and between study and control groups. No significant retinal abnormality was detected by light microscopy in either group. CONCLUSIONS: The film adhered well to the retina with no signs of ocular toxicities. Further study is warranted for possible means of patching retinal breaks.     

Intravitreal injection of hyaluronidase cannot induce posterior vitreous detachment in the rabbit

PURPOSE: To investigate whether intravitreal injection of hyaluronidase can induce posterior vitreous detachment (PVD) in the rabbit. METHODS: One eye each of 12 New Zealand white rabbits received intravitreal injection via the pars plana of 20 IU of hyaluronidase (0.1 mL reconstituted in sterile balanced salt solution [BSS]) into the midvitreous cavity. The fellow eye of each rabbit received a vitreous injection of 0.1 mL of BSS. At 3 and 6 months after intravitreal injection, four and eight rabbits were killed, respectively, and the eyes were enucleated. After fixation, scanning electron microscopy was performed to study the vitreoretinal interface. RESULTS: At 3 and 6 months after injection, scanning electron microscopy showed that the retinal surfaces in eyes that received either hyaluronidase or BSS were covered with vitreous collagen fibers. No eyes, even those that received hyaluronidase over a period of 6 months, had the smooth retinal surface consistent with a bare internal limiting lamina that suggests the development of PVD. CONCLUSION: Hyaluronidase cannot induce PVD in the rabbit over a 6-month period after vitreous injection.     

透明质酸酶诱导玻璃体后脱离的实验研究

目的 研究透明质酸酶诱导玻璃体后脱离的安全性和有效性。方法 选取成年健康纯种新西兰白兔15只，随机分为A、B、C3组。随机选取每只兔的一眼为实验眼，另一眼为对照眼。A组玻璃体腔注入透明质酸酶5IU／0．1mL，B组透明质酸酶10IU／0．1mL，C组透明质酸酶20IU／0．1mL，对照组眼内注入0．1mL BSS。结果 A组术后所有眼均未见玻璃体后脱离；B、C组于术后第5周出现玻璃体后脱离，并且无出血、渗出或视网膜脱离等并发症发生。结论 浓度为10IU／0．1mL和20IU／0．1mL的透明质酸酶玻璃体腔注射后第5周可形成玻璃体后脱离，并且安全有效。     

Experimental prophylaxis of Staphylococcus aureus endophthalmitis after vitrectomy: the use of antibiotics in irrigating solution.

PURPOSE: To test the efficacy of clindamycin and gentamicin in irrigating solution during vitrectomy to prevent experimental Staphylococcus aureus endophthalmitis. MATERIALS AND METHODS: Thirty-six New Zealand white rabbits were divided into six groups. Vitrectomy using two different irrigating solutions was followed by intravitreal injection of S. aureus: Group 1, balanced salt solution (BSS) followed by 1,000 colony-forming units (CFU) S. aureus; Group 2, BSS fortified with clindamycin, 10 microg/mL, and gentamicin, 8 microg/mL (CGBSS), followed by intravitreal injection of 1,000 CFU S. aureus; Group 3, BSS followed by 2,000 CFU S. aureus; Group 4, CGBSS followed by 2,000 CFU S. aureus; Group 5, BSS followed by 4,000 CFU S. aureus; and Group 6, CGBSS followed by 4,000 CFU S. aureus. The eyes were examined clinically after surgery. Vitreous samples were cultured and histologic studies were performed. RESULTS: Severe endophthalmitis developed in all eyes in Groups 1, 3, and 5 (not given antibiotics). No endophthalmitis developed in Group 2. In Group 4, five of the six eyes were normal and one eye had endophthalmitis. In Group 6, one eye had clear vitreous and fundus, three eyes had moderate vitreous haze, and the other four eyes demonstrated severe endophthalmitis. Bacterial growth in Groups 1, 2, 3, 4, 5, and 6 were 4/4, 0/4, 6/6, 1/6, 4/6, and 2/8 eyes, respectively. CONCLUSION: When 1,000 to 2,000 CFU S. aureus were injected after vitrectomy, clindamycin and gentamicin in the irrigating solution significantly diminished the intraocular inflammation and the rate of positive bacterial culture. Clindamycin and gentamicin in the irrigating solution were not significantly effective when 4,000 CFU bacteria was injected; however, the degree of inflammation was less severe than in the control group.     

Retinal toxicity of intravitreal kenalog in albino rabbits

PURPOSE: To evaluate possible toxicity of intravitreal Kenalog (commercial triamcinolone acetonide) to the retina of albino rabbits. METHODS: Forty-three albino rabbits were injected intravitreally with 0.1 mL of experimental solution to the right eye and 0.1 mL of saline to the left eye (control). Rabbits in Group A (n=28) were injected with 4 mg/0.1 mL of Kenalog suspension; rabbits in Group B (n=8) were injected with 0.1 mL of Kenalog vehicle; and rabbits in Group C (n=7) were injected with 4 mg/0.1 mL of triamcinolone acetonide. Rabbits were examined ophthalmoscopically and by electroretinogram (ERG) recordings before and at different time intervals after injection. At the end of follow-up, animals were killed and the retinas were prepared for light microscopy. RESULTS: Thirty-eight rabbits completed 4 weeks of follow-up. Follow-up for 8 and 17 weeks was completed by 29 and 3 rabbits, respectively. Intravitreal commercial Kenalog or its vehicle alone caused approximately 50% reduction in the ERG b-wave amplitude at the end of follow-up. Pure triamcinolone acetonide caused only mild (up to 14%) reduction of the ERG b-wave amplitude. Histologic examination of retinas exposed to Kenalog or its vehicle showed severe damage to all retinal layers in areas close to the site of Kenalog injection. CONCLUSIONS: Intravitreal injection of 4 mg Kenalog suspension is retinotoxic to albino rabbit eyes. The vehicle of Kenalog is probably the main cause of this toxicity.     

Prevention of endophthalmitis by collagen shields presoaked in fourth-generation fluoroquinolones versus by topical prophylaxis

PURPOSE: To compare the prophylaxis of collagen shields presoaked in antibiotics versus antibiotic drops after bacterial anterior chamber challenge. SETTING: John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. METHODS: Forty rabbits received bilateral 0.03 mL intracameral injections of Staphylococcus epidermidis (5 x 10(8) colony-forming units). Four groups of 10 rabbits had their eyes randomized to receive (1) 3 mg/mL gatifloxacin (Zymar) drops or shield in Zymar, (2) Zymar drops or shield in 10 mg/mL gatifloxacin (Tequin), (3) 5 mg/mL moxifloxacin (Vigamox) drops or shield in Vigamox, or (4) balanced salt solution (BSS) drops or shield in BSS. Each eye received Zymar, Vigamox, or BSS 4 times 1 hour before injection. The antibiotic-BSS was administered every 2 hours (5 doses total). One day later, signs of endophthalmitis were scored under the slitlamp. RESULTS: Groups 1 and 2 had significantly lower endophthalmitis incidences (total score > or = 8) than the BSS controls. Shield scores were not significantly different from those of the counterpart drops. The comparison between drops was not significant (P = .0513); the difference between shields (P = .0232) and the post-comparison Zymar versus BSS shields (P = .0021) were significant. CONCLUSIONS: Topical therapy with gatifloxacin before and after intraocular bacteria challenge led to lower incidences of endophthalmitis in rabbits. Prophylaxis with presoaked collagen shields was not statistically different than that with topical drops.     

Performance comparison of the Alcon Legacy 20000 straight and flared 0.9 mm Aspiration Bypass System tips

PURPOSE: To compare the efficiency of surgical procedures using 2 phacoemulsification tips. SETTING: Wolfe Clinic, Marshalltown, Iowa, USA. METHODS: A randomized prospective study of 256 consecutive cases was conducted. The patients were adults having phacoemulsification by a modified in situ fracture technique. All cases were done by 1 surgeon using the Alcon Legacy 20000 phacoemulsification machine with high-vacuum cassettes and tubing. One of 2 45-degree Aspiration Bypass System (ABS) phacoemulsification tips was used. The straight tip has a 0.9 mm outside diameter (n = 127). The flared tip has a 0.76 mm outside diameter shaft that flares to a 1.02 mm tip (n = 129). Measurements at the time of surgery included metered phacoemulsification time, percentage power used, total phacoemulsification time, and milliliters of balanced salt solution (BSS(R)) used. RESULTS: No posterior capsule tear, vitreous loss, incision thermal damage, incision leak, or suture closure occurred. There were no cases of iris aspiration into the working end of the phacoemulsification needle; however, the iris was aspirated into the ABS opening of the flared tip in 1 case. Similar measurements for the straight and flared tips included, respectively, metered phacoemulsification time, 1.4 minutes each; mean power percentage, 41% and 39%; total phacoemulsification time, 2 minutes 11 seconds and 2 minutes 15 seconds; and overall BSS volume, 77 mL and 75 mL. The anterior capsule tear rates for straight (5.5%) and flared (1.6%) tips were similar. CONCLUSIONS: The flared ABS phaco tip with a 0.76 mm shaft outside diameter provided the physical advantages of shaft diameter reduction and required ultrasonic energy expenditures, BSS volumes, and surgical times similar to those of the straight ABS ultrasonic tip with a 0.9 mm outside diameter.     

5-氟尿嘧啶聚乳酸微球防治实验性增生性玻璃体视网膜病变的效果观察

目的评价5-氟尿嘧啶（5-Fu）聚乳酸微球防治增生性玻璃体视网膜病变（PVR）的效果.方法分别将5-Fu聚乳酸微球和5-Fu原料粉末注入兔眼玻璃体腔后,测定前房水中5-Fu浓度,观察5-Fu聚乳酸微球体内释放特性.将健康家兔48只随机分为3组：1组为5-Fu聚乳酸微球组;2组为无药物的聚乳酸微球对照组;3组为5-Fu原料粉末对照组.以巨噬细胞注入家兔玻璃体腔建立PVR动物模型后,1、2、3组分别向实验家兔左右两眼玻璃体中后部注入：1组注入5-Fu聚乳酸微球的BSS混悬液0.2 ml（相当于25 mg微球,含5-Fu 2.6 mg）;2组注入含有25 mg无药物聚乳酸微球的BSS混悬液0.2 ml;3组注入5-Fu注射液0.2 ml（含5-Fu 2.6 mg）.评价其防治PVR的效果.结果 5-Fu聚乳酸微球较5-Fu原料粉末消除半衰期明显延长,半衰期为379.05 h,清除率明显降低.1组中有2只眼因晶状体损伤排除试验;3组中有4只眼因发生急性药物毒性反应而排除试验.药效实验表明：21及28 d,2组视网膜脱离发生率为62.5%、71.9%;3组为64.3%、78.6%;1组为13.3%和13.3%,其中1组的视网膜脱离发生率降低,与2、3组比较,差异有统计学意义（P〈0.01）,2、3组视网膜脱离发生率的差异无统计学意义（P〉0.05）.结论 5-Fu聚乳酸微球具有明显的缓释作用,玻璃体腔植入可有效防治巨噬细胞诱发的实验性PVR.     

Pathology of exogenous mycotic endophthalmitis (author's transl)]

The histological examination of five bulbi with exogenous mycotic endophthalmitis reveals invasion of fungi confined to the anterior segment including the anterior vitreous body. Hyphae are found within abscesses, and granulomas respectively. The posterior eye remains relatively free, however a posterior vitreous detachment always exists together with a massive retraction of the vitreous gel. These findings should be kept in mind if intravitreal injections of amphotericin-B, or a vitrectomy are considered. After intravitreal injections of amphotericin-B no retinal lesions could be revealed.     

Toxicity study of erucylphosphocholine in a rat model

PURPOSE: To investigate the effect of intraocular erucylphosphocholine (ErPC) on the retina, the retinal pigment epithelium (RPE), and the choroid in an in vivo rat model. METHODS: Adult male Brown Norway rats were injected intravitreally with ErPC dissolved in balanced salt solution (BSS) at a final concentration of 10 or 100 microM with BSS serving as control. Adverse effects on the anterior and posterior segment were assessed by slit-lamp biomicroscopy and ophthalmoscopy. Retinal toxicity was assessed by electroretinography (ERG), retinal ganglion cell (RGC) quantification, and histology 7 days after intravitreal administration of ErPC. RESULTS: There was neither a statistically significant difference in the clinical examination nor in the ERG waves of treated versus control rats 7 days after intravitreal administration of ErPC. Correspondingly, the number of RGC after BSS injection did not differ significantly from ErPC-injected animals. Histologic sections of the posterior segment of 10 and 100 microM ErPC-injected rats did not show any signs of retinal toxicity. Electron microscopy did not display a difference between the 10 microM and the control group. Only the 100 microM-injected animals showed a discrete irregularity of the Müller cell and the retinal ganglion cell cytoplasm at the ultrastructural level. CONCLUSIONS: ErPC can safely be injected into the vitreous of adult rats at a concentration of 10 microM without any retinal toxicity. Even a 10-fold increase in ErPC concentration leads only to a discrete cytoplasmic irregularity of the innermost retinal layers.     

人工晶状体植入术后并发眼前节毒性综合征

目的：通过分析眼前节毒性反应综合征(toxic anterior segment syndrome, TASS)患者的临床表现, 寻找TASS的患者的发病原因、治疗方法及预后。

方法：通过前房及玻璃体穿刺培养的方法排除感染性细菌性眼内炎,考虑为TASS患者6例7眼,局部应用抗生素和糖皮质激素眼液及玻璃体腔注射万古霉素1mg及头孢他啶2mg治疗,观察治疗后效果。

结果：所有TASS患者前房液及玻璃体液培养均未见细菌生长。TASS患者1例2眼经局部类固醇激素眼液治疗,5例5眼经前房冲洗、玻璃体腔注药后,前房炎症明显好转,视力提高,随访6mo,未再出现眼部异常表现。查找致病因素时根据排除法考虑为消毒锅的原因,及时清洗和更换滤网后发生率明显降低。

结论：尽管TASS是眼前段手术的罕见并发症,及时查找致病原因,早期正确诊断及积极有效的治疗预后良好。